Muffler



E'. E. BRYANT March 4, 1958 MUFFLER Filed 0G13. l2, 1953 O G O @O0 E5@ w/W/ MUFFLER Edwin E. Bryant, Stoughton, Wis., assiguor to Nelson Muiiler Corporation, Stoughton, Wis., a corporation of Wisconsin Appiieation ctober 2, 1953, Serial No. 383,783

5 Claims. (Cl. 181-57) The present invention relates to a novel mufer, and more particularly to a muler for internal combustion engines.

An object of the present invention is to provide a novel mufller which is particularly effective when used in connection with large truck motors, diesel engines, or

the like.

Another object of the present invention is to provide a novel muffler of the above described type which is constructed in a manner so as to increase the useful life thereof.

Other objects and advantages of the present invention will become apparent from the following description and the accompanying drawings, wherein:

Fig. 1 is a perspective View of a muler embodying the principles of this invention;

Fig. 2 is an enlarged cross sectional view taken along line 2 2 in Fig. l;

Fig. 3 is a cross sectional view taken along line 3-3 in Fig. 2; and

Fig. 4 is an enlarged fragmentary cross sectional view showing a novel feature of this invenion in greater detail.

Referring now more specifically to the drawings, wherein like parts are designated by the same numerals throughout the various figures, a muffler 10 embodying the principles of this invention includes an elongated tubular housing l2 constructed of steel or other suitable materials. One end of the housing is closed by a ange 14 which is preferably Welded entirely around its circumference to the housing, as at 16, and the opposite end of the housing is closed by a flange 18 welded thereto, as at 2i?. The interior of the housing is divided into three chambers 22, 24, and 26 by means of partitions or anges 28 and 3h, each of which is spot welded at spaced points around its periphery to the walls of the housing.

An exhaust gas intake pipe 32 extends into the interior of the housing i2 through an opening 34 formed in the end partition 14. The opening is preferably bounded by an annular ilange 36 which is welded to the inlet pipe or tube, as at 38. As shown in Fig. 2, the inlet tube extends through the chamber 22 and an aperture 40 in the partition 28 and terminates in the chamber 24. The portions of the inlet tube 32 disposed within the chambers 22 and 24 are perforated, as indicated at 42, for the purpose described hereinbelow. An outlet tube 44, perforated as at 45, extends through apertures 46 and 48 in the partitions 28 and 30 and is provided with an adapter section Sti extending through an aperture 52 in the end partition 14. The aperture S2, like the above described aperture 34, is preferably bounded by an annular ange 54 which is welded to the outlet tube adapter section, as at 56. A spacing collar 5S surrounds the adapter section 5i) and ts within the tube 44 and is welded to the tube and adapter section, as at 60.

ln accordance with a feature of this invention, the useful working life of the muffler 10 is substantially increased by applying a coating 62 of porcelain or suitable vitreous materials to all of the interior and exterior surited States arent O faces of the muier, as shown best in Fig. 4. The porcelain coating substantially increases the life of the mufer both from a corrosion resistance standpoint and a heat resistance standpoint inasmuch as the porcelain coating prevents corrosive materials from contacting the metal parts of the muffler and also prevents oxygen from contacting the metal which would cause oxidation when the muffler is heated. The porcelain coating is preferably applied by dipping the muler in a bath of porcelain before the end plate or flange 18 has been applied to the housing. Excess porcelain is then drained from the interior of the muffler, and drain holes 64 and 66 are provided to facilitate drainage from the chambers 22 and 24. After the interior of the muier has been drained, the end plate 18, which has also been dipped in porcelain, is applied to the housing l2.

The operation of the above described mufiler structure is as follows. The gases entering the inlet tube 32 are primarily directed through the initial relatively short chamber 22 and discharged into the relatively large chamber 24, where they expand and then pass into the large end chamber 26 through an aperture 68 in the partition 30. The relatively large volume of gas in the chambers 24 and 26 then forms a cushion to reduce and modify the shock waves coming from the engine. Furthermore, it is noted that the gases are confined in the inlet tube for a relatively short time, or, in other words, the gases are permitted to expand in the relatively large chambers 24 and 26 soon after they enter the mufller. This reduces exhaust back pressure and permits the engine to operate at higher eliiciency. The exhaust gases from the chamber 26 are discharged from the mufer through the outlet tube 44. However, it should be noted that by reason of the perforations in both the inlet tube 32 and the outlet tube 44, the gases actually discharged through the exhaust tube adapter 50 include not only expanded gases coming from the end chamber 26, but also expanded gases coming from the chamber 24 and somewhat less expanded gases passing through the apertures in the inlet tube of the initial relatively small chamber 22 and the apertures in the outlet tube. This intermingling of the gases which have been expanded various amounts further breaks up the impulses coming from the engine, and in combination with the particular tube and partition arrangement, effectively muifles exhaust noises. Furthermore, it appears that the above described porcelain coating on the metal parts of the muffler provides a dampening effect for improving the muiliing characteristic of the device.

From the above description, it is seen that the present invention has provided a muffler of simple construction which is capable of effectively operating to muffle engine noises, particularly when used in connection with large truck engines and the like. ln addition, it is seen that by reason of the porcelain coating, the present invention has provided a muier having an increased operating life.

While the preferred embodiment of the present invention has been shown and described herein, it is obvious that many structural details may be changed without departing from the spirit and scope of the appended claims.

The invention is claimed as follows:

1. A muler, comprising an elongated tubular metal housing, a pair of metal end caps closing opposite ends of said housing, a plurality of perforated metal partitions disposed within said housing and dividing the interior of the housing into a plurality of axially spaced chambers, an exhaust gas inlet tube extending through one of said end caps, and extending through a chamber adjacent said one end cap and opening into a second chamber, an exhaust tube extending through said one end cap, and extending through said chamber adjacent said one end cap and opening into another of said charnbers, said inlet and exhaust tubes having a plurality of apertures therein located so that gases passing out of said inlet tube may enter the exhaust tube from each of sai chambers, and a substantially impervious coating oi' vitreous material covering substantially all exposed in terior and exterior surfaces of the mufiier to prevent corrosion and oxidation of the muffler.

2. A muier, as defined in claim 1, wherein said chamber adjacent said one end cap is relatively smali as compared to other of said chambers, whereby gases passing through apertures in the inlet tube through said relatively small chamber and into the exhaust tube are expanded less than gases passing through said exhaust tube from said other chambers.

3. A muffler, as defined in claim 1, wherein said inlet tube is relatively short and opens into a relatively large chamber, whereby exhaust gases may be relatively rapidly expanded to reduce exhaust gas back pressure and whereby expanded gases in the relatively large chamber provide a cushion for absorbing impulses from an engine to which the muffler is connected.

4. A muffler, comprising an elongated tubular metal housing, metal end caps closing opposite ends of said housing, metal partition means for dividing the interior of said housing into at least three chambers, an exhaust gas inlet tube extending through one of said end caps, and extending through a` first chamber adjacent said one end cap, and extending through one of said partition means defining said first chamber and opening into a second chamber, an exhaust tube extending through said one end cap, and extending through said first and second chambers, and opening into another of said chambers, another of said partition means having an opening therein for permitting the llow of exhaust gases from'said Second chamber to said last mentioned chamber, whereby exhaust gases may pass from the inlet tube through said second and last mentioned chambers and out through said exhaust tube, said inlet and exhaust tubes having perforations therein communicating with said rst chamber, whereby a portion of the exhaust gases may pass from the inlet tube through said first chamber to the exhaust tube, said exhaust tube having apertures therein communicating with said second chamber, whereby gases may pass from said second chamber into said exhaust tube, and a substantially impervious coating of vitreous material covering substantially all exposed interior and exterior surfaces of the muier to prevent corrosion and oxidation of the muier.

5. A mufller, as defined in claim 4, wherein said second and last mentioned chambers are relatively large as compared to said first chamber, whereby gases passing into the exhaust tube from the various chambers have been expanded various amounts.

References Cited in the tile of this patent UNITED STATES PATENTS 1,148,900 Hunt Aug. 3, 1915 2,065,343 Moore et al. Dec. 22, 1936 2,133,876 Steenstrup Oct. 18, 1938 2,324,706 Jacobson July 20, 1943 2,395,005 Kuhn Feb. 19, 1946 2,553,306 Dietrich May 15, 1951 2,614,647 Bryant Oct. 21, 1952 2,711,975 Wainer et al. June 28, 1955 2,716,271 Higgins Aug. 30, 1955 OTHER REFERENCES Publication: Automotive Industries, page 37, May 21, 1932. 

